In such a prior art safety belt retractor known from DE 10 2009 014 999 A1, the load limiter contains a brake with which relative rotation between the element to be braked and a support element produces a rise in pressure inside a pressure chamber, which is then converted into an brake actuating force. A medium which is filled into the pressure chamber may be silicone, or more specifically a silicone granulate, the particle diameter of which is approximately 0.2 to 0.3 mm and by means of which an axially mobile displacement element can be partly sheared. The displacement element displaces the medium provided in the pressure chamber, thus cause the rise in pressure in the pressure chamber, which is then converted into the brake actuation force. In this prior art load limiter, load limitation is performed by the brake only, and not by the medium.
The purpose of the load limiter is to limit the forces acting during an accident between the safety belt and the vehicle passenger wearing the safety belt and who is moved further forwards in the motor vehicle seat.
The object of the invention is to provide a belt retractor in which the load limiting effect is automatically adjusted, depending on the vehicle passenger data and the severity of the respective accident.
This object is achieved, according to the invention, by the features of claim 1.
The dependent claims contain advantageous developments of the invention.